That’s the warning delivered to the Department for Business, Energy and Industrial Strategy (BEIS) by trade body Energy UK, which said its members are likely to be hit with large fines that are largely unavoidable.

The letter, seen by the Press Association, said: “There is the prospect that suppliers will face significant financial penalties for non-compliance of legal obligations as a result of factors outside their control.”

The deadline was proposed in September after a consultation regarding the government’s original target of installing a smart meter in every home by 2020 – the rollout aims to help reduce energy usage, emissions and bills by making consumers more aware of their electricity usage.

However, the scheme has been plagued by setbacks, including older smart meters ceasing to function and confusion regarding whether a smart meter is mandatory or optional.

Energy UK warns the best-case scenario for 2024 is that 68% of homes have a smart meter installed.

It also suggests lower-than-expected consumer appetites to actively seek the installation of smart meters has significantly slowed uptake.

Climate Change Minister Lord Duncan recently told the BEIS Select Committee that it could soon become “very expensive” for households to refuse to change to smart meters.